For purposes of product returns and order filling, it is important to be able to sort and count products accurately and quickly. Such products, for example magazines and packages, have historically either been manually sorted and counted by human operators or manually scanned to read an affixed code, counted and then sorted by the human operator according to a product disposition signal provided from the product scanner according to the scanned code. One drawback experienced with these primarily manual methods for separating, counting and sorting is that total product processing time for sorting and counting is a function of each human operator's ability to accurately sort and count products and/or efficiently scan the products to obtain the affixed bar codes for sorting and counting. Familiarity with the product and the signals indicating the disposition of each product also factor into the processing time. An additional drawback of the conventional manual separation, counting and sorting process is its susceptibility to error resulting from careless human operators directing products into improper bins. These drawbacks result in errors in the counting of products and delays in the sorting process thereby reducing net product throughput of, and profits for the sorting and counting operation.
The most commonly used code affixed to products is the bar code. As is well known, there are two common orientations of bar codes, a ladder code orientation and a picket code orientation. These two orientations are easily distinguished from each other; a ladder code is comprised of a plurality of horizontal bars (like the rungs of a ladder) parallel to a top or bottom edge of the product, and a picket orientation is comprised of a plurality of vertical bars (like the pickets in a fence) parallel to a side edge of a product. Bar codes may be affixed to the product at any one of a number of locations on any outside product surface.
The goals of all sorting and counting operations are accuracy, low cost and high throughput product processing. The conventional manual prior art sorting and counting systems utilize an omnidirectional scanner, similar to that commonly used in grocery store check-out lines, to read the bar code off packages positioned with either a picket or ladder orientation. Omnidirectional scanners, however, are very expensive and further require that each encoded product in the singulated stream pass through the scanning zone at a relatively slow rate or be scanned more than once. Manual sorting and counting using omnidirectional scanning systems has therefore proven to be expensive and slow. Accordingly, there is a need for an inexpensive automated apparatus for accurately scanning both picket and ladder oriented bar codes from a singulated stream of coded products moving at a relatively high throughput rate.